What does the X mean on the light? Donna Post October 27, 2016 19:48 Updated Design feature-helps show where the on/off button is. It is also how to adjust through the different modes Related articles How do I charge my light? What is COB? Are Kryptonite front and rear lights waterproof? How do I know if it’s a set or not? I have lost my USB cable. What kind of accessories can I use? Comments 0 comments Article is closed for comments.